Sweet science lets researchers measure urine levels in public pools

The wide use of artificial sweeteners in our food has given a team of scientists a golden opportunity to answer a horrifying question: “Just how much pee is in the pool?”

Researchers from the University of Alberta tested 31 pools, diving tanks and hot tubs in two cities between May and August 2014.

They were looking for traces of acesulfame-K (ACE), a common sweetener found in prepackaged foods.

ACE doesn’t break down in the digestive system and is only excreted from the human body in urine.

The sweetener can be found in varying concentrations in natural waterways and tap water, but no one had checked for it in public pools before the team decided to take the plunge.

The results that have trickled out are chilling for anyone who enjoys a swim: every single pool had ACE in it, at concentrations ranging from 4 to 571 times higher than what was found in tap water, leaving little doubt that it was only getting there in one way.

In one case, a pool about a third the size of an Olympic swimming pool was found to contain an estimated 75 litres of human urine — roughly equivalent to the daily output of 50 adults.

Researchers Lindsay K. Jmaiff Blackstock, Wei Wang, Sai Vemula, Benjamin T. Jaeger, and Xing-Fang Li wrote that they hope their work helps improve public health. While urine leaves the human body sterile, it can interact with disinfectants in pools and contribute to conditions like asthma and cause eye irritation.

The report cited research showing 19 per cent of adults admit to having peed in a pool at least once.

The findings were published in Environmental Science & Technology, a journal put out by the American Chemical Society.